Freezing apparatus



1953 E. P. WENZELBERGER 2,657,549

FREEZING APPARATUS Filed April 4, 1950 s Sheets-Sheet 2 "Wm M,

INVENTOR ATTORNEYS 1953 E. P. WENZELBERGER 2,657,549

FREEZING APPARATUS Filed April 4, 1950 v s Sheets-Sheet s INVENTOR BELWOOD F? WENiELBERGER ATTORNEYS Patented Nov. 3, 1953 UNITED STATESMAT-BN1 OFFICE FREEZING APPARATUS -.-Application April's 1950,:SerialNoe-153,806

-1 .This .-.invcntion relates to a -:new "and novel method r ofdehydrating solutions and/ or suspensions Jayv freezing and :apparatusfor carrying 2,0111? .the .process. More particularly, it relates tofreezingsapparatus for rrapid :formation-mfpure ice at .lowdifferentials .offaemperature between freezing solution iandacoolan-t.nstillumore par- .ticu1ar1y,.-it relates to rfruit juice freezingapparatus.

In the'freezing of ice undertnormal conditions, the meat itransfer isefiected by imposing. a large temperature-difierentiahbetween.-thecoolant and the water. The guantityzof heattransferred ,per square footofiheat-transfer surface undersuch conditions :is large Land,thessolefactors .to be considered are temperature.ofwatenthequantity ofwater, and the iternperaturelof thecoolant.

Freezing of pure ice from solutions containing dissolvedxmaterial suchassaltsnand sugars and solidfmatterssuchas pulp fiberspresentssan-entire1y:.different problem.

By pure ice .is .:meant crystal .ice substantially free .QfRoccludedsolution and/.or solids. t-Puredee may be distinguished-readily from=white.ice .because. ofwtheldefinitely.fine-crystal formation gpre-:senting 1a z-m-ass i of individual crystals in unagglomerated form.

It has been-discovered :that ;.pure :ice can only be frozen iromaziruitJuice solutions t-andzother :heat1sensitiveacon positions when.the'rtemperature idifferential :hetween the solution .and 113116coolant is of the order of 5 to 7" F.

wIt .1116 :a particul-ar .rohlect of -.this .invention toprovide:arapidrandteconomical meansandzmethtod of uremovin-g water fromsfruit Juices, -beer, wines, pharmaceuticals such as antibiotics, heatsensitive xresins, :cofiee, milk, Land vegetable j uices. This list isnot exclusive, but is merely supplementally.

.1It.-is.also -an-.o.bj.ect rofthisinvention to provide va methodtwhereinithe solvent of :a solution is progressively .frozen attemperatures whicnresult in the formation cofsfineesolvent crystals.

It 115 .a .f.urther..1obiect .of this invention to. ,provide atstepwisefreezing ,process whereinthe solution isprogressivelyiiehjdrated'byremovalofiice therefrom.

.Ihisiresults in ,a -..concentration from which nothing has been removedexce iit the Water and the water removal has 'been effected Without.detriment to vitamins, volatile oils, taste, .,and

other characteristics of the v product.

it is .a. sstillffurther iolo'iect or ;the, 'present' in vention'ztoprovide a stepwise ffreezingjprocess wherein "the solution is subjectedto successive and. lower rtemperature freezing steps, each one. smallItemperature differential "between initial freezing and.concentratedsolutionJfreezing ,poin't.

"ltlisalsoman objecttoassociate with this stage freezing system aliighvolume heat exchangecavpacity in association with means for rapidly.changing the "liquid .Jinterface in contact with 'freezing surfaceswith means for ample cooling and with .means .for providing a 'flow ofrefrigerant capable of removing the heat as fast as it i transferred"through the heat exchange interface. The ice thus'formed is afine'crystalline ice slush having a large ice crystal area.

It is to be understood thatif white iceforms itis exceedingly di'fiicultto "remove "and has a tendency to "clog and plug 'thesmechanism andcauses great "difi'iculty "in "the entrainment of juices and solids.

It? is another advantage 'Of'this method that it is .unnecessarytofortify the resulting product with raw juice. It'is the currentcommercial practice withvacuum 'treated orange juiceyas an "example, "tofortify the juice "when dehydrated by adding about "25 .of raw "juice.

Concentration by mymeth'od can'loe carried out to ahigh degree with no"injury to -the juice and"'it;canbe reconstituted "in the hands .of theuser'hy the'addition'of requisite'water. Nothing ,is lost from the juice"except'watenand nothing i's added. Heat iselimina'ted'so"as' nottodisturb heat "sensitive materials being'processe'd.

It 'is a purpose this invention to provide apparatus for ifreezing icefrom "solutions such as fruit juices "which bring the time *foreffective "freezinginto a reasonableyprocessing period.

'It*is anotherpbject o'fthisinvention to provide apparatus for freezingice from solutions'such 'as fruit juices wherein the ratio "of surfacearea' to liquidvolume'is =in-the ratio of greater than 1 square'foot per-2 gallons of solution.

It "is-a further object of this invention to provide apparatus whichrequires a minimum of "floor space while having a' large "processingcapacity.

-In -the"1ight of the foregoing, various other obj ects and-advent ageswill be apparent' from i the following description taken in connectionwith the drawingsfin which:

Figure 1 is =a side levational view showing "the internal -arrangementof a freezing chamber and disclosing one freezing *uiiitin verticalcross*section;

Figure 1s a top plan view 'of the "apparatus of Figure -I;

' Figure is"a*'side ==e1evationa1 "view-of "another embodiment of theinvention also disclosing one freezing unit in vertical cross section;and

Figure 4 is view along the line 3-4; of Figure 3.

Briefly, the process of this invention comprises lowering thetemperature of a liquid composition below the solidification temperatureof the solvent therein, continuously supplying ice crystal nuclei tosaid composition by continuous separation of initiated ice crystals fromthe heat transfer surface, agitating the composition to control the icecrystal size and growth, and removing the ice crystals leaving theliquid composition at least partially dehydrated.

The principle upon which this process is based is the formation of pureice crystals, a large proportion of which are formed as crystal nucleiand immediately after formation are scraped off the freezing or heatexchange surface.

The crystal nuclei are distributed to grow in the composition underagitating conditions controlling the crystal size, thus avoidingformation of white ice which oocludes solids, freezes to largeagglomerates and prevents clean separations of ice and liquid.

In this freezing operation, there is a limited quantity of water whichis convertible to solid ice at a temperature imposed upon any identicalfreezing step. This quantity of water or freezing potential is thatamount which must be removed to produce a composition having a freezingpoint which is equal to the imposed temperature.

Elimination of this water as ice crystals comes about through growth ofice crystal nuclei to ice crystals separable from the liquid compositionby means of, for example, a centrifuge.

Since white ice results from growth of crystals to too great a size, thecontrol of crystallization is, a vital factor. The greater the number ofice crystals growing in the composition, the quicker the dissipation offreezing potential and the smaller will be the average size icecrystals.

The instant invention by removing ice from the cooling surface as it isformed, distributes throughout the freezing composition a large numher iice crystal nuclei which grow as long as there is solidifying potential.

Ice formation being continuous at the cooling surface, a continuousstream of ice crystal nuclei are being formed and being separated fromthe surface for distribution in the composition.

The result is a continuously multiplying number of growing crystalswhich are so numerous that, under the conditions of agitation, none growlarge enough to alter their character from crystal ice to white ice.

When there is a relatively small differential between the initial iceforming point of water of the solution and the temperature maintained inthe container by the refrigerating medium, the transformation of waterto ice takes place within a time interval, within which interval the iceforming point of the solution is lowered to approximately thetemperature imposed upon the solution in the container and ice formationceases, the time interval being determined by the rate of heat transferto the refrigerating medium.

The heat transfer, it has been found, can be effected while maintainingsmall temperature differentials, if a ratio of one square foot ofrefrigerating surface for each one to one and a half gallons or less ofliquid is maintained.

When such ratios are held substantially constant, the time period, forexample, 12 to 20 minutes, remains substantially constant regardless ofthe quantity of liquid being processed.

To be commercially feasible t -e process must have a high volumecapacity. In this system the capacity is great because the time intervalfor maximum ice formation is under direct control at all times and theseries of containers integrated in their operation, so that liquid onlystays in each tank long enough for formation of the maximum ice contentor ice crystals of maximum size for that temperature, and as aconsequence thereof reaches the maximum concentration for that stagebefore the resultant solution is moved to the next container, whosetemperature is lower than the temperature at which ice will again formin the solution. The result of this repetitive operation is to producegra ual but uniform crystal growth.

If this uniform heat transfer were to be ac complished without anyagitation, large crystals would form. The type of agitation I usecreates small crystals and serves two other functions.

A wiping blade agitator removes any ice which otherwise would cling tothe heat exchange surfaces of the vessel. This is removed as fast as itforms. This ice immediately acts as a seeding process to grow morecrystals throughout the volume of the liquid. This wiping agitation isperformed by a relatively slow speed agitator of about R. P. M.

The other agitator ,(at higher speed, i. e. about 800 to 990 R. P. M.)prevents large crystal growth. producing small pure ice crystals. Italso prevents the crystals so formed from floating to the top of theliquid where they would aggregate and coalesce together to form a solidmass of ice which would occlude juice.

By forming large numbers of individual small crystals, continually inmotion in the liquid, they remain unattached to each other with auniform dispersion of ice crystals in the liquid medium. Being a liquidwith ice slush it becomes easy to transport it or flow it through pipesfrom one piece of apparatus to another.

The tabulation given later is suggestive of the ratio of temperatures.It has been found that these temperatures, while typical, represent arule of action that secures the desired result.

The maintenance of temperatures, which are continually being lowered,maintains the ice as individual crystals, solid in form and easilycentrifuged.

This is in marked distinction to the results obtained where the ice iswarmed for partial melting, or where white ice is formed having juiceand solids occluded therein, and the ice takes on a physical characterwhich will disrupt the proc ess.

I have found that by first cooling a liquid hearing solids and adjustingthe diiference between the temperature of the liquid and the temperature of the refrigerant by a small differential of approximately 5 to 7degrees, and then agitating by means of both agitating units the liquidbearing solids or dissolved material or both, the liquid willimmediately form ice very rapidly.

Continuous agitation prevents localized cooling and ice formation at thenormal congealing point, particularly in large crystals and in whiteThis operational method secures the result of fine crystals in a largemass without occluding some of the solution or solids in the ice.

In order to obtain these fine crystals in a relatively pure form withoutsolids, the temperature inf itheiceoling liquitlrm machsuccessiveflzeezing step must beheldipractinallyizatmcconstariticemperaturejftherizemperaftureiheingrmaimainedaata mredeterminedzlower itemperature, doelow thezice iorming temperature.of ithecsolution.

Jmcrderttoaspeedztheiicescrystaliformation'nnrthese monditions, theesys'temizmust' mossess high heat exchange :capacity. Ebe :bmught :aboutsby i'first, iagitation, which ilarings aaboutrrapi'dachangeofdylreiliqliid interfaceuonsconitactiwith the ffreezenurfaues;secoridlyfioyemainrtaining zaflmtioi of zonezsquarejeotrofzcoolingsurrface iforrea'ch uoneito aoneeami a ;:ha1f rgallons -:ofsolution:heingtreatedpand;ithirdlygbyzmaintainvingithe'flowcofrrfiigerantccapablesoftrremovingcarelatively large quantity of heat.

.1 also. lfindi it: important sthatcthe majtor'qoortion .innn'any:instancesnffahe :stagestof progressivelyfloweringithettemperaturewhalltbeaboveizerogand :IJ- alsorfindIitimportant:that'theisuecessive stages be at 1 relatively :small:temperature nteductions, such? aszab out: 5 :eandi 7 iF. ,2andithatztheztempera- .turerof the liquid initheeecondfs'tage should beieDproximatel-ybtheitemperature:of thezrefrigerant in the firststageandmocon. Itwill:be understood ithat these difierentials mill waryiwith athezliquids and -the-solids, tbut vthe principleco'f' the:uperation remains i-the :same.

By avoiding extremes itemperature, rquick xfreezingrand-bymaintainingreasy stagesmfilowerdng temperatures :and zmodestdifierentials Ebe- .tween :the-rrei'rigerantandzthevliquiduvhilezcausing agitation, a steadyfreezing:or.zsmalliioeicrys- -.tais* will:taketplace:andrrapidxiehydration can be leffectediwithoutoccluiiingtother liquiiisranli-ssolids than'twater.

eByzstarting, ass-in" the ca-seinfzorange.fjuicegatra tank temperature:of123 :Ezrzleoveezero; with :an outside temperaturemflmirf.,fthentaitemperature ninrithe next 1tank:of 118.2F with: an nutsidetemperature of13 F.,fthen :a :tanki temperature :of 133 nwith van:ontsiiie'itemperaturezof 43 3F.,1and thezfourth tanksai temperaturetonfi ?:F.-'-:withian outsidextemp'eratureaofiyligandmiheZIastTtarik,

a temperaturecof i Withtantnutsrde temperarture "of .2 Lfree:clearlicetcrystals nan .rbeise- :oured :that rare:zeasilrmaintainEd-lby the :stirrer, :irrfreezmovement, withiminimum'crystalzsizei and ithe amaximumzfreezin gsc apacity: f orithe :temperature applied. 'lThis'tzprinciple:of zar'multiple series 10f steps,starting thatemperature just'Fabout-"at the-freezing pointrofzthe juicerand zprog'ressively reducing itrand-iprogressively removing fiwater byifreezinggenablesthis result'toibe secured.

The apparatus capablel'mf icarryingimut tthe process of "(this inventioncomprises ea chamber {provided with "inlet and mutletfpassages zand :amultiplicity of cylinders,";each cylinderrheingzpro- ,vided wwith:inlets and 'outlets '7 for refrigerating ,medium.

Each cylinder or freezingunitfcomprisesiazcircular shell and at leastone freezing'zsurface :scrapen-zthe-shell. andscraperscbeing:adaptedffor .movement relativetaeachaother aboutzatconnnon axis.

FIhe -chamber1is :preferabiy -xzircular air more than four-freezingcylinder-stare to :he installed .therein. :For four rfreezingzcylindersizaisquare chambengives-the bESlFVOlllIIIB distribution.

.Applicantrhas :discoveredtthat for itan'ks iof tliis :ch-aracterPhaving :atratio inf igallonsfoflliquid per .unit :of :surface :areato)? approximately I .4 $0 2 gallons;per squareifootpfreezing ofepure'ice' ioccuriat .;a 25 F. :zdifierential Pat anyicapacity in dswvailablein ltheirefrigeration circulating runit. Tanks preferably areconstructed having :a-ratio cofrgalionsnfdiquid perunit-of surface areain "the range of approximately .-1:5 egallons per .square .zfoot.

il his ratio calculation maybe-illustrated simply by icalculationsrelative to a itankv l feet high 731K144 inches-inf diameter-havingidisposed there- -in 7 rotatmg -cylinders --each 1 :-foot :in'diameter. Each cylinderwillrhave 12.56 =square feetofsuriace. Eachcylinder will takewup the space of w23-.5;-gall0ns. ..'The tank wouldhave 'a total capacity offipproximately '316 gallons. i Deducting:theespace for.w7-.rcylinders, the holding capacity willJbe.3l6-,;ga1lons1645:1515 gallons. Thus gallons ;per;.'square;fo'ot of'coolingisurface.

zrInzthendrawing, the tank is illustrated as .haviing lvcylinders:disposed therein. The ratio of volumeof liquiditosurfacearea'is thatwith :4 cylinders in place the ratio is 1 gallon .per squareifootofsurface. 'With 3 :cylinders 'in place the ratiois approximately1.25i'gallons per square foot 'ofrsurface. 'withizwcylindersxin placetheratio riszapproXimatelyflflBgallons per square foot of surface.

ViReferring 1130 the fdrawings :an'd :specific'ally to Figures 1-fandr2,thelnumeral'iil :designates a1circular shell. shell 'I 0 isrsupportedibysteel framezworkrl-tl. Chamber lllfisfprovidedwith aconicalbottomz-section l2 converging to a'shell outlet 43. Shell [:0 is also,,provided with arzliquid' inlet .14. .shellwl'il i-stprovided at-thetop-withva'flang-e l5.

.Mounted on the :top iof .shelLHl-is :a plate 46 secured too-flange It5by.-isuitable means ll-such :as:studs.

The -iapparatusiasillustrated is .shown adapted to positioning fouridentical and identically mountedifreezing units, :26, 2 I, 22 and and.a central axial stirring uniti24. To-accommodate these units,,platev I5is provided with anaxial aperture I 8 .and cfoureidentical apertures i9.ra idially positioned. .In the description of the. ap-

paratuslre'ference will .be madeto a (single .unit iexceptaslo'therwiseispecified, it; being understood that "the -..parts would.carry like descriptions.

On the top sidean'd adjacent theaperture t9 the surface is undercut at25to form a seat to receive lahorizontal extension 2'6 of a support arm.21. Support arm "2? has secured. thereto by suitablemeansiil, 'such asscrews or rivets, .a scraper .bladele 'iwhich' rides in contact withlbOllh the sides and "bottom' of refrigeration cylinder 3 2.

Support arm 2] .is provided with a "horizontal projection 30 at thebottom. "Projection 33 is adapted "toreceive a shaft "or pin'33 on thebottom of the refrigeration cylinder .32. This pin ,33 serves to "holdthe bladezfimounted on the support 2 I in'fixed'pressure "contact withthe sur- "face Ofitherotatingcylinder32.

"Cylinder 32 isfsupportedfor rotation "by being s'ecureditoa.tubular'member 3 l'suchas by elding SEi. Tubularmembertdhasmountedthereon a suitable-packing andthe 'spaced inner races "3'T'and 38 "ofball bearingsets "39 and "49. The outer races H *and 42 "of ball bearingsets 'are positioned in *a "mounting or ball bearing houslug T3.

Housingfii is a unit of "greater 'horizontalsur- "face-area than-theapertures 19 for which the housing-E3 "is positioned so-asto provideforat- *tachment *or securing *means hereinafter de- 'scribed.

Housing 43 is ir'iternally' borezi for passage of Jiheahnvenzangeiiformhichiheatitransfer capacity T tubular-member 34therethrough an'd is-coun'terbored to form a shoulder 44 upon whichrests the outer race 4I.

Tubular unit 34 extends beyond the ball bearing races and is externallythreaded as at it. Adjacent the race 353 there is mounted on unit 34 asprocket 4? having a set screw 48 to prevent the sprocket from rotatingindependent of tubular unit M. The sprocket 41 is further secured by alock nut 39. Sprocket 4'! is mounted for actuation by a chain belt notshown.

Mounted within the tubular unit 34 is a conduit 50. This conduit 5% isstationary and adapted for a sliding fit. To prevent leakage ofrefrigerant at the point where conduit 53 emerges from unit 3 3, thereis mounted a brass support ring 5| and suitable packing 52, around whichis a packing nut 53 threadedly mounted on tubular unit 34. Packing unit53 may be secured against working loose by suitable means 54, such as aset screw of plastic material, a, locking nut, or other suitable means.

Conduit 5i: is an outlet pipe for refrigerant supplied to cylinder 32through a pipe 55 mounted within conduit 5% and extending to a pointadjacent the bottom of cylinder 32. To obtain rigidity and preventlateral pressure from forcing the rotating mechanism out of alignment,conduit 58 is passed through a retainer plate 6S mounted on a pair ofstuds BI and 52.

Stud iii is threaded at its lower end. The lower end threads E3 engagethe threads 5:2 of aperture 65 in plate It. Stud SI passes through onecorner of mounting 33 in a sliding fit arrange ment. The upper end ofstud 6! is threaded and plate 65 vertically positioned by nuts 55 andEl.

Stud I52 is like threaded at its lower end and threadcdly received in athreaded recess 63 in mounting 43. At its upper end bolt 62 is alsothreaded. There is threadedly mounted on each stud E2 a verticalpositioning nut 59.

Seated on the four nuts Iiii is a plate lil. Plate if! is centralaxially bolted to receive a shaft iI. Plate "Iii is counterbored at E2to receive the races of the ball bearing IE4 which support shaft 1!. Theinner endl of plate is seats on plate is and the two held rigidlybetween nut 65) and a nut i3.

Surrounding shaft TI is a spacer sleeve 74. The upper portion of shaftit carries a pulley I5 secured to the shaft by a set screw It. Thepulley i5 is adapted to be driven by a belt "I? from a source of powernot shown.

Shaft "ii extends downwardly through aperture Iii in plate It to a pointadjacent the conical bottom it of shell l0. Adjacent the bottom of shaft"ii there is mounted a transversely positioned stirring arm I8 securedthereto by suitable releasable means 19 such as a bolt.

Inasmuch as shaft ii is adapted for relatively high rotational speed, asecond point for support is provided where said shaft passes throughplate iii. Support is provided by means of ball bearings 39, the outerrace BI of which is adapted for press fitting into aperture I8. Theraces are supported on the underside by a projection 82 of a plate 83which is likewise adapted for a press fit into the lower portion ofaperture is.

Plate 33 seals aperture I8 against leakage of liquid. The ball bearingsare held against dislocation upwardly by mountings 53, a corner of eachof which contacts the outer race 8|.

Figures 3 and 4 represent another embodiment of the invention whereinthe refrigeration cylinders are stationary and the scrapers are rotated.The numeral I00 designates the liquid container 8 or shell, having aconical bottom portion IUI and an axially positioned outlet I I32.

Shell I00 is provided at the top with an external flange I03. Flange N33is provided with spaced threaded bores I04. Shell IE9 is also providedwith a top cover H35 adapted with a flange lot and secured to shell Ittby suitable means I01 such as hex head bolts.

Positioned between shell Hi0 and cover N35 is a gasket plate H33 adaptedto extend entirely across said shell. Gasket plate M3 is apertured atI09 to receive a central axially positioned shaft H0 and at fourradially spaced positions III to provide passage for the fourrefrigerating cylinders I I2 and associated mechanism as hereinafterdescribed.

Cover IE5 is provided at the central axial position with a truncatedcone shaped outward projection H5. Projection H5 is axially bored andadapted to receive bushings i It and I I? which in turn receive theupper portion lid of shaft III].

Intermediate its ends shaft 5 It is provided with a collar I I9. Theupper end I I3 of shaft I It carries a sprocket I26 secured to the shaftby suitable means I2 I such as a set screw or pin.

Adjacent the collar H9, there is mounted on shaft H0, a pinion gear I22.At the lower end of shaft III) there is mounted a transverselypositio-ned mixer blade I23.

As best seen in Figure 4, top cover I65 is provided with four identicalapertures IZ i. In each aperture I24, is secured, as by a press fit, arefrigerating cylinder I I2.

Cylinders II2 are provided internally with central axially bored closuremembers I25. Mounted within member I25 is a conduit I25 secured againstleakage by a press fitted member I21. Mounted within conduit 523 so asto leave an annular space for removal of refrigerant from cylinder H2 isa pipe I28 which delivers refrigerant from a source not shown.

On the exterior of cylinder H2 is secured by suitable means such aswelding, a flange I36. Flange I38 is a base upon which rides a gear I3Ihaving a loose sliding fit with cylinder I I2.

Gear I3I is adapted to engage pinion gear i22 and, to be rotatedthereby. The tooth bearing flange of gear I3I has secured to theunderside thereof the projections I35 of three spaced arms I36. Arms I36at their lower extremity are provided with horizontal projections whichare joined to one another through an axially positioned plate I33. ArmsI35 are the bases for scraper blades I39 which ride in contact with thesurface of cylinder I I2.

It will be understood that this invention is susceptible to modificationin order to adopt it to different usages and conditions and,accordingly, it is desired to comprehend such modifications within thisinvention as may fall within the scope of the appended claims.

I claim:

1. Freezing apparatus for dehydrating fluid compositions to a slushwherein the water constituent is removed in the form of substantiallypure ice crystals, said apparatus comprising a shell, an axial outlet inthe bottom of said shell, an axially mounted stirrer with mixing bladepositioned adjacent said outlet, a plurality of cylinders mounted withinsaid shell, conduit means connected to the interior of said cylindersand to a source of refrigerant for introducing refrigerant into saidcylinders, and scraper means for the outer surface of each of saidcylinders, said scraper means contacting both the sides andbottomnsurfacesrcteach -cylinder,:satdecylinders and scraper means beingadapted 'for movement-relative to each other.

2. Freezing :apparatus .for ejdehydrating :fluid compositions to a slush:wherein theawateraconstituent is removed in theform ofgsubstantiallypure .ice :crystals, said apparatus rcomprising '.a shell, a pluralityof rotatable: cylinders :mounte'd therein having. a ;.total surface:area which 2pm vides more than one square: foot eof surface zper gallonor-fluid in :said shell,;con'duit. means cons. nected to the: interiorof.saidacylmderseandatoua source: of :refrigerant for.introducingrefrigerant intor said: cylinders,1:means or:-rotatingsaid'oy-linders; a plurality :ofvscrapen unitsnprovided with scraperblades amounted in :positions :rela-. tive to saideylinders andavhereintheir respective scraper units are arrangedrto position ithei'bla'de incontact withiithe outer surfacecfssaid cyline. ders, said scraperbla'des *beingiinxcontactwvith both the: sides ando tom s rf-acesoft-each cylinder.

3.. Free in ap ara u d h a :fl compositionstona, slush wherein the waterconstiutent is removedin't'he'form of substantially pumice-crystals,said apparatus comprising a shell, a :pluralityof rotatable cylindersmounted therein having -a total surface area which --provides more'thanone square 2 foot of suri-acegper gallon of fluid in said shell, conduitmeans connected tothe interior of said cylinders and to a sourceofrefrigerantfor introducing refrigerant into said cylinders, means-forrotating saidcylinders simultaneously and-at "the same speed: ofrotation-e, plurality of scrapertunits provided withscraper 2 bladesmounted fixed positions relative: to said cylinders and-= wherein theirrespective ascraper units are arranged to position the blades in contactwith the outer surface of said cylinders, said scraper blades being incontact with both the sides and bottom surface of each cylinder.

4. Freezing apparatus for dehydrating fluid compositions to a slushwherein the water constituent is removed in the form of substantiallypure ice crystals, said apparatus comprising a shell, a plurality ofrotatable cylinders mounted therein having a surface area which providesmore than one square foot of surface per gallon of fluid in said shell,conduit means connected to the interior of said cylinders and to asource of refrigerant for introducing refrigerant into said cylinders,means for rotating said cylinders simultaneously and at the same speedof rotation, a plurality of scraper units provided with scraper bladesmounted in fixed positions relative to said cylinders and wherein theirrespective scraper units are arranged to position the blades in contactwith the outer surface of said cylinders, said scraper means contactingboth the sides and bottom surfaces of each cylinder, an axially mountedstirrer with mixing blade, and means for rotating said stirrer at apredetermined speed.

5. Freezing apparatus for dehydrating fluid compositions to a slushwherein the water constituent is removed in the form of substantiallypure ice crystals, said apparatus comprising a shell, a cover closingthe top of said shell, a stirrer, means connecting said stirrer to asource of power, a plurality of cylinders fixedly supported by saidcover, conduit means connected to the interior of said cylinders and toa source of refrigerant for introducing refrigerant into said cylinders,a gear rotatively supported on each cylinder; scraper rmeans providedwith scrapers blade; carried: by s each gear and: adapted to contact thesurface of each .cylinder, said scraper-umeanscontacting-boththesidesandbottomsurfaces or each cylindertandmeans'ior driving said gear sand:thereb-y rotate sa-id scraper means.

fidlF-reezing .:apparat-us :for dehydrating fluid compositions .to "a:slush wherein the Water constituent removed in the Storm ofsubstantially pure ice crystals, said apparatus "comprising a shell, :acover closing the top 'of said :shell, a stirrer, argear onsaid stirrer;means connecting-said stirrer to a source of power a-pluralityofzcylinders "fixedly supported by said -;cover, conduitmeanszconnectedizto the interior otsa'id cylinders and to :a source ofrefrigerant tor s introducing refrigerant intosaid cylindera-a gear 'oneach cylindenandadapteditormeshtwith said gear mounted on' said stirrer,and scrapermeans. carried by eaclrgearmounted:oneachcylindergsaid-scraper meansacontacting both:thesideszandbottomsur,faces of each cylinder.

:Freezingzapparatus for freezingfluidcompositionsfto'auslushcontainingpure frozen solvent comprising .--a shell, an axial bottomoutlet for said-shell,;a.;covericlosing -the top of :said s-hell, liquidinlet rneans in: said ,cover,-a smallcentral axial aperture inusaidcoven a ball- :bearing supporti forsaa-shatt receivedin 'sa id aperture,aplurality of 4 equilaterally spaced round aper-tures radially disposedfrom said central aperture, a support; member suspended fromtsai'd coverand extending vertically :the-edge-ofeach spaced aperture, a pluralityof 'housi-ngseach of-greater area than aispaced: aperture: secured to"the exteriono-fi said: cover and -adapted with axial boreimaiignmentrwith the axis o f said -aperturea ball bearing sets mountedin the bore of said housings, a plurality of cylinders each having atubular projection extending beyond said cover and supported by saidball bearings in rotatable position, a sprocket mounted on said tubularprojections, means for driving said sprockets, blades mounted on saidsupport members in contact with the surface of said cylinders,stationary outlet conduit extending through said tubular projection intothe top of each of said cylinders, refrigerant inlet pipes extendingthrough said outlet conduit to a point adjacent the bottom of saidcylinders, vertical support members mounted in said housings, a platesupported by the vertical support of each group adjacent the centralaxis, said plate being central axially apertured in alignment with thesmall aperture on said cover and adapted with a ball bearing support fora shaft, a shaft extending through said aligned small apertures andsupported by the ball bearing sets therein, a mixer blade mounted on theend of said shaft within said shell, a pulley mounted on the oppositeend of said shaft, and belt means for driving said pulley.

8. Freezing apparatus for freezing fluid compositions to a slushcontaining pure frozen solvent comprising a shell, an axial bottomoutlet for said shell, liquid inlet means for said shell, a coverclosing the top of said shell, an outwardly extending projection on saidcover in central axial position, a plurality of equilaterally spacedapertures radially disposed from the central axis of said cover, aplurality of cylinders each fixedlymounted in an aperture from saidcover, a collar on each of said cylinders, a gear mounted on each saidcylinder and adapted for vertical support by said collar said gear beingadapted to contact and be rotated by said pinion gear, support meanssecured to said gear, scraper means mounted on said support means andadapted to contact the exterior surface of said cylinder, an axialaperture in said projection, bushing means in said aperture, a rotatableshaft received in said bushing and extending to a point adjacent theaxial outlet, a transverse blade secured to said shaft at the endadjacent said outlet, a shoulder member mounted on said shaft adjacentthe interior surface of said cover, gear means mounted on said shaftadjacent said shoulder, a sprocket mounted on the opposite end of saidshaft, and means for driving said sprocket.

9. Freezing apparatus for freezing fluid compositions to a slushcontaining pure frozen solvent comprising a shell, an axial bottomoutlet for said shell, liquid inlet means for said shell, a coverclosing the top of said shell, an outwardly extending projection on saidcover in central axial position, a plurality of equilaterally spacedapertures radially disposed from the central axis of said cover, aplurality of cylinders each fixedly mounted in an aperture from saidcover, a collar on each of said cylinders, a gear mounted on each saidcylinders and adapted for vertical support by said collar, said gearbeing adapted to contact and be rotated by said pinion gear, a plu-.

rality of support members secured to said gear at one end and to eachother at the opposite end, a plurality of blades mounted on said supportmembers and adapted to contact the exterior surface of said cylinder, anaxial aperture in said projection, bushing means in said aperture, arotatable shaft received in said bushing and extending to a pointadjacent the axial outlet, a transverse blade secured to said shaft atthe end adjacent said outlet, a shoulder mem- 12 ber mounted on saidshaft adjacent the'interior surface of said cover, gear means mounted onsaid shaft adjacent said shoulder, a sprocket mounted on the oppositeend of said shaft, and means for driving said sprocket.

10. Freezing apparatus for dehydrating compositions comprising water asa constituent by freezing out said water as substantially pure icecrystals which are substantially free of occluded portions ofthecomposition being treated, said apparatus comprising a shell, aplurality of cylinders mounted in said shell, conduit means connected tosaid cylinders and a source of refrigerant for introducing therefrigerant into said cylinders, means comprising a scraper forpreventing ice crystals from forming thereon, said cylinders and scrapermeans being adapted for movement relative to each other, said scraperblades being in contact with both the sides and bottom surfaces of eachcylinder.

ELWOOD PAUL WENZELBERGER.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,633,712 Ribi June 28, 1927 1,818,896 Kohr Aug. 11, 19311,951,923 Cartoux Mar. 20, 1934 1,954,518 Downer Apr. 10, 1934 1,996,781Winton Apr. 7, 1935 2,136,062 Suss Nov. 8, 1938 2,241,726 Krause May 13,1941 2,297,786 Lindblom Oct. 6, 1942 2,306,602 Harrington Dec. 29, 19422,415,585 Genova Feb. 11, 1947 2,529,959 Pedersen Nov. 14, 19502,559,205 Wenzelberger July 3, 1951

